Portable Magnetic Field Mapping Measurement System based on Large-Scale Dipole Magnets in HIAF

The High-Intensity Heavy-Ion Accelerator Facility (HIAF) is a significant national science and technology infrastructure project, constructed by IMP, to provide primary and radioactive intense beams for nuclear and related research. Large aperture, high-precision, and warm-ion superconducting dipole magnets are extensively utilised to achieve high beam intensities. However, the traditional Hall point measurement platform faces limitations such as magnet volume, measurement environment, and the range of good field regions in the measurement of large dipole magnets, especially huge superconducting dipole magnets, leading to poor operability, low measurement efficiency, and significant errors in secondary positioning accuracy. This paper introduces a new magnetic field mapping measurement system, which introduces ultrasonic motors capable of operating under strong magnetic fields (<7T), and can realize portable, efficient and high-precision magnetic field measurement. After system debugging, the SRing dipole magnet prototype was measured. The system's accuracy and efficiency were verified through comparison with traditional Hall probe measurement systems. On this basis, magnetic field distribution and integral excitation curve measurements of all 11 HFRS warm-iron superconducting dipole magnets and 3 HFRS anti-irradiation dipole magnets were carried out and completed, achieving the testing objectives.